Calmchaos

Hello.
I have been getting the 3 piston I have right now ready to drop into the block.
I was putting the rings on the other day and getting them all lined up.
The bottom and top went in and had a little bit of play in them, which I would describe as normal.

The middle one with the little shelf on it is REALLY tight. I had to make sure I put it on in the correct position because I couldnt spin it around the piston.

Im not even sure if it will go all they way in when I put the ring compressor on it.
Does this sound normal?

Thanks
-Brett

944bucky

Are you using differnet pistons?

I would force things of this nature. Is there an orientation? Is the shelf facing to right direction?

Calmchaos

yeah I made sure that I faced the shelf in the correct direction.
And these are the same pistons. Just had them cleaned and had the rods checked for roundness.

Calmchaos

??

Kurt R

The book says vertical play for groove 2 is 0.04-0.072mm on Mahle pistons, 0.05-0.082mm for KS. Tight would not be right.

Calmchaos

Fantastic.... what could be wrong?
I know I have the right rings....

Calmchaos

I re-cleaned the ring groves with broken rings and they went in much easeir.
I just found that odd because I had the pistons cleaned at the machine shop.
The three pistons I have are in and moving nicely.

StoogeMoe

You might want to clean the grooves some more with some solvent and a toothbrush until they are perfectly clean. Alot of carbon builds up in there. Measure the gap again and make sure it's within spec before installing.

____________________________________
1986 944 NA - Guards Red - 91k miles - minty
1983 944 NA - Platinum metallic - 3000 mi beginning a new life
1985.1 944 NA - Guards Red - donor car
1984 911 Carrera Coupe - Guards Red (gone, but not forgotten)
"If you're not living on the edge, you're not living"

ekeeton

I'd say you have a gripe with your machine shop.

Calmchaos

The pistons were clean enough to eat off of.... I dont know what the deal was.